CHICAGO – During the 2008 Beijing Olympics, changes in air pollution were associated with changes in biomarkers of systemic inflammation and thrombosis (formation of blood clot) as well as measures of cardiovascular physiology in healthy young persons, according to a study in the May 16 issue of JAMA, a theme issue on Global Health.

“Air pollution is a risk factor for cardiovascular diseases (CVD), but the mechanisms by which air pollution leads to CVD is not well understood. Hypothesized mechanisms with associated biomarkers include systemic inflammation and thrombosis or endothelial [thin layer of cells that line the heart and certain vessels and cavities within the body] dysfunction,” according to background information in the article. “As a condition for hosting the 2008 Olympic Games, the Chinese government agreed to temporarily and substantially improve air quality in Beijing for the Olympics and subsequent Paralympics. This provided a unique opportunity to use a quasi-experimental design in which exposures and biomarkers were measured at baseline (pre-Olympics), following a change in pollution (during-Olympics), and then repeated after an expected return to baseline (post-Olympics).”

David Q. Rich, Sc.D., of the University of Rochester, New York, and colleagues conducted a study to determine whether markers related to CVD pathophysiological pathways (biomarkers for systemic inflammation and thrombosis, heart rate, and blood pressure) are sensitive to changes in air pollution. The researchers measured environmental air pollutants daily and also measured various biomarkers and other measures (heart rate, blood pressure) in 125 healthy young adults before, during, and after the 2008 Olympics (June 2-October 30). The biomarkers measured included those associated with systemic inflammation (fibrinogen, C-reactive protein [CRP], white blood cell [WBC] count) and thrombosis or endothelial dysfunction (platelet activation markers P-selectin [sCD62P] and soluble CD40 ligand [sCD40L] as well as the adhesive endothelial glycoprotein von Willebrand factor).

The researchers observed statistically significant improvements in SCD62P levels (by -34.0 percent), and von Willebrand factor (by -13.1 percent). Changes in the other outcomes were not statistically significant after adjustments for multiple comparisons. In the post-Olympic period when pollutant concentrations increased, most outcomes approximated pre-Olympic levels, but only sCD62P and systolic blood pressure were significantly worsened from the during-Olympic period. “The fraction of above-detection-limit values for CRP was reduced from 55 percent in the pre-Olympic period to 46 percent in the during-Olympic period and reduced further to 36 percent in the post-Olympic period. Interquartile range increases in pollutant concentrations were consistently associated with statistically significant increases in fibrinogen, von Willebrand factor, heart rate, sCD62P, and SCD40L concentrations.”

“Although these findings are of uncertain clinical significance, this study provides quasi-experimental, mechanistic data to support the argument that air pollution may be a global risk factor for CVD.”
(JAMA. 2012;307[19]:2068-2078. Available pre-embargo to the media at www.jamamedia.org)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Francesca Dominici, Ph.D., and Murray A. Mittleman, M.D., Dr.P.H., of the Harvard School of Public Health, Boston, write in an accompanying editorial that “China’s dilemma, like many countries with emerging industries, is how to reconcile rapid economic growth with environmental protection.”

“In recent decades, China has achieved industrialization and urbanization. However, China has been much less successful in maintaining the quality of urban air. Several factors challenge the implementation of air pollution controls in China: heavy reliance on coal as a main heating system, especially in subsidized housing; lack of political incentives for trading slower growth for less pollution; economic factors: most Chinese factories and power plants run on extremely thin margins and fines for polluting are generally lower than the cost of controlling emissions; and economic transformation of the landscape, from ubiquitous construction sites to the rapid expansion of the nation’s vehicle fleet. If air pollution in China and other Asian nations cannot be controlled, it could spread to other continents. A recent study by Lin et al provides compelling evidence that Asian emissions may account for as much as 20 percent of ground-level pollution in the United States. Clean air is a shared global resource. It is in the common interest to maintain air quality for the promotion of global health.”
(JAMA. 2012;307[19]:2100-2102. Available pre-embargo to the media at www.jamamedia.org)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

# # #

Sign In

Special News Release >

FOR IMMEDIATE RELEASE – FEBRUARY 12, 2015 CHICAGO – The JAMA Network launched its new journal, JAMA Oncology, today with a robust collection of articles reporting on new research, opinion and reviews. The featured research included: “Hereditary Diffuse Gastric Cancer Syndrome,…

Special News Release >

The weekly JAMA Report is now available at http://jama.newsmarket.com/. Every Tuesday at 11 a.m. Eastern time, a new JAMA Report will be posted. The JAMA Report is a weekly video and audio new release highlighting a study appearing in the…

Special News Release >

The JAMA Network journals have recently published several articles on breast cancer. Here are the news release headlines, with links to the releases, studies, and JAMA Report videos: JAMA: Many Breast Cancer Surgery Patients Do Not Receive Shorter, Less…

Special News Release >

The JAMA Network journals have recently published articles on telemedicine. Here are the news release headlines, with links to the releases, studies, a JAMA Report video for one article and an author podcast for another: JAMA Psychiatry: Telemedicine Collaborative Care…

Special News Release >

JAMA has recently published several articles on sickle cell disease. Here are the news release headlines, with links to the releases, studies, and JAMA Report video for two articles: Sickle Cell Trait Among African Americans Associated With Increased Risk…

Special News Release >

FOR IMMEDIATE RELEASE – November 3, 2014 CHICAGO – John S. Rhee, M.D., M.P.H., a professor and chairman of the department of otolaryngology and communication sciences at the Medical College of Wisconsin (MCW) in Milwaukee, has been named the next…

Special News Release >

FOR IMMEDIATE RELEASE – SEPTEMBER 22, 2014 CHICAGO – The JAMA Network will launch a new journal, JAMA Oncology, to publish important cancer-related research and named Mary L. (Nora) Disis, M.D., a professor of medicine at the University of Washington,…

Special News Release >

FOR IMMEDIATE RELEASE – SEPTEMBER 8, 2014 CHICAGO – Stephan Heckers, M.D., M.Sc., chair of the psychiatry department at Vanderbilt University in Nashville, Tenn., has been named the next editor-in-chief of JAMA Psychiatry, one of nine specialty journals in the…

Special News Release >

FOR IMMEDIATE RELEASE – AUGUST 29,2014 CHICAGO – Melina R. Kibbe, M.D., professor of surgery and vice chair of research in the department of surgery at Northwestern University Feinberg School of Medicine, has been named the next editor-in-chief of JAMA…

Special News Release >

JAMA has a new series of articles, the JAMA Guide to Statistics and Methods. These articles will provide explanations about statistical analytic approaches and methods used in research reported in JAMA articles, to help readers better understand clinical research reports. These…